Generally, I've always argued that songs that fade-out are cop-outs, work out how to end the song, or at least do a fun cut out (a la I want you (she's so heavy)) but fading out...feels like you couldn't figure out how to properly. I think a few Smiths songs are guilty of it actually, That Joke isn't Funny anymore for example, though that does a fade back in first...
And yet somehow I do quite like It's Working by MGMT (I thought second album, while flawed, a lot better than first...but maybe just me)
Any other songs where a fade-out feels appropriate? I can't quite work out why I think it works there and yet annoys elsewhere, wonder if anyone has any ideas